Alan Murray is next in line

Under Mr Dougal's leadership, Hanson, once the sprawling and aggressive conglomerate that set the pace in the takeover boom of the 1980s, has concentrated on its core construction materials operations.

Alan Murray, president of the firm's US building materials operation, is to step into Mr Dougal's shoes.

Changing times

Hanson chairman Christopher Collins gave Mr Dougal much of the credit for Hanson's recent transformation.

Over the past six years, the firm has spun off a vast range of non-core businesses, including Imperial Tobacco, US chemicals firm Millennium and a number of energy companies.

Hanson is more focused now

The company applied its own brand to its remaining businesses, completing its evolution from a holding company - the investment vehicle for ex-chairman Lord Hanson - into a relatively straightforward industrial firm.

Mr Dougal, a 50-year-old Scot, was finance director of Hanson for much of the 1980s.

He said that he planned to return to the business world, after a break.